Coherence of Bessel-Gaussian beams propagating in the turbulent atmosphere
I.P. Lukin
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: бесселев пучок, вихревой пучок, оптическое излучение, атмосферная турбулентность, когерентность, радиус когерентности, интегральный масштаб степени когерентности, Bessel beam, vortex beam, optical radiation, atmospheric turbulence, coherence, coherence length, integral scale of coherence degree
Abstract
Coherent properties of vortex Bessel-Gaussian beams propagating in the turbulent atmosphere are theoretically studied. The approach to the analysis of this problem is based on the analytical solution of the equation for the transverse second-order mutual coherence function of the optical radiation field. The behavior of coherence degree, coherence length and integral scale of coherence degree of vortex Bessel-Gaussian beams depending on parameters of a beam and characteristics of the turbulent atmosphere is particularly considered. It is shown that the coherence length, and integral scale of coherence degree of a vortex Bessel-Gaussian beam essentially inversely depend on the topological charge of a vortex beam. Thus, in process of increase in a topological charge of a vortex beam the increase in reduction of values of coherence radius and integral scale of coherence degree of a vortex Bessel-Gaussian beam becomes less. The value of the given effect also essentially depends on characteristics of the turbulent atmosphere: at weak and strong fluctuations of optical radiation the given effect is not great, it reaches a maximum in the transition region from weak to strong fluctuations of optical radiation.
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